While Americans debate the U.S. role in Syria, President Obama is meeting with the leaders of the world's biggest economies. They've gathered for the G-20 summit in St. Petersburg, Russia. The official focus of the meeting is global economic growth, but there, too, Syria is the issue of the day.

President Obama is hoping to find some international support for a military strike on Syria in response to last month's deadly chemical weapons attack. One leader who won't be backing that plan is the summit's host, Russian President Vladimir Putin. From St. Petersburg, NPR's Scott Horsley reports.

SCOTT HORSLEY, BYLINE: There was a long line of limousines outside the Constantine Palace today as world leaders arrived for the summit meeting. Russia's Vladimir Putin welcomed his fellow presidents and prime ministers, ushering them inside into the opulent Marble Hall. President Obama was one of the last to arrive, and he exchanged a somewhat stiff handshake with the Russian leader.

Obama has little hope of changing Putin's mind about Syria. But deputy national security adviser Ben Rhodes says the president does hope to reach some of the other leaders sitting at the big, round summit table.

BENJAMIN RHODES: We would never expect to achieve full consensus among the countries here because Russia just takes a different position. But in terms, in particular, of our friends, our allies, our partners around the world, we believe it's important for people to raise their voices on behalf of international norms that countries around the world have signed on to for many years.

HORSLEY: The first leader Obama buttonholed was Japanese Prime Minister Shinzo Abe. Obama says they share a joint recognition of the situation in Syria.

PRESIDENT BARACK OBAMA: The use of chemical weapons in Syria is not only a tragedy, but also a violation of international law that must be addressed.

HORSLEY: The administration would prefer to act through the United Nations, but Russia has repeatedly blocked that avenue. Despite that, the president says he and Putin are still able to cooperate on other issues.

But the two men's stilted greeting today is another sign of their personal disconnect. Andrew Kuchins of the Center for Strategic and International Studies says it's a terrible personal relationship.

ANDREW KUCHINS: My image for the summit is kind of the hold-your-nose summit. I really think these two guys don't like each other at all.

HORSLEY: Skirting the Putin problem, Obama's set to meet privately tomorrow with Chinese President Xi Jinping and French President Francois Hollande. So far, France has been the United States' staunchest ally on Syria. Most of these conversations are taking place on the sidelines of the G-20 where the official agenda is focused on economics.

Syria is not the only source of tension here. Brazil's president, Dilma Rousseff, is said to be furious about a report based on leaked NSA documents that U.S. surveillance included monitoring of Rousseff's own email traffic. Through an awkward bit of protocol, Obama finds himself sitting next to Rousseff at the summit. He acknowledged this week advances in surveillance technology bring greater potential for abuse.

PRESIDENT BARRACK OBAMA: We have to balance the ends with the means. And just because we can do something doesn't mean we should do it.

HORSLEY: Some U.S. lawmakers would say the same about Syria. Prospects for a congressional vote authorizing a military strike remain uncertain, especially in the House, despite the backing of leaders from both parties. Rhodes says the White House will keep working to win over skeptical lawmakers. He says Obama personally telephoned five senators yesterday, both Democrats and Republicans, asking for their support.

RHODES: What we're seeing each day is an increasing number of members who are convinced that a military response is necessary. But we're going to continue to make the case to members. We understand the obligation that we have to provide them with information. We'll keep doing that, and we're confident that we'll get a resolution passed.

HORSLEY: The administration is not overconfident though. Today, the White House cancelled a planned trip to California next week so the president can focus on making his case to lawmakers as they return from their August recess. Scott Horsley, NPR News, St. Petersburg, Russia. Transcript provided by NPR, Copyright NPR.